Seems to work fine for me, but I'm low volume and high intensity. Its not like I plan to sleep this way though, its just how it works out I guess. I have read that left to our own devices humans are essentially biphasic sleepers, waking for a short period once during the night and a short time for sleep in the early afternoon. So I just hang my hat on that so I can convince myself that I'm "normal" .

Wow guys I'm struck by how early a lot of people seem to be rising? Is this a natural thing or a work thing? I tend to go to bed about 11.30 and wake at 7am so getting aroundabout 7 hours a night once I get to sleep, but I have huuuge trouble getting out of bed! I'm UK based and in Scotland so not sure if it's just the fact the clocks went back and the weather is getting cold, or whether I need to address another underlying issue. Either way, it's a big struggle to get out from under the warm snuggly duvet! I went through a phase of trying to get to bed early and rise early, but I'm currently writing a phd thesis and find the quiet evenings the most productive time for me.

I get up at 4:45am to get to gym by 5:15, workout until 7:15, shower at gym and to office by 8. If I didn't go to gym before work, I would sleep until 7:20 in order to be to work on time at 8.